The Twin Connection
by charliexedd
Summary: Kate is stuck on a case and even Castle is out of ideas. Unwilling to let go Castle comes up with a madcap idea that reminds Kate just how unintentionally brilliant he can be. Set sometime late in S4 but before 47 secs. No spoilers.


**A/N: Just my attempt to bring out Beckett's first love for Castle - his writing. It got kinda buried as I wrote the rest of this story around the idea, but it was that thought which spawned the rest.**

**As someone not naturally gifted when it comes to putting thoughts down on paper (writing is hard!) I liked the irony of the idea - although now I'm a little worried if I'm using irony in the correct context so I'm off to check...enjoy!**

* * *

Detective Kate Beckett stared at the murder board in front of her, hoping for some new revelation to jump out; some new thought that would give them a lead, however faint, in this case. But, no matter how hard she stared, no matter how she arranged and rearranged the information they had gathered nothing leaped out at her, no hint of a clue or idea as to where to go next.

It was late and the 12th was quiet. She'd sent Ryan and Esposito home hours ago and even Castle had eventually left after she had threatened to arrest him for stalking her. She'd still had to promise that she would leave the precinct herself within the next half hour before he finally gave up and went home. Beckett glanced down at her watch; that had been more than 2 hours ago.

She knew she should go home, get some sleep and start again fresh tomorrow. But she always hated it when a case dried up, when all the leads that she and her team dug up went nowhere. Not all murder cases could be solved, she knew that better than most, but Beckett hated every case that came across her desk which could not be solved. The thought that for those cases the killer would be out there, knowing they had gotten away with murder, always made her grind her teeth in frustration.

Beckett looked at the DMV picture of the dead woman, which hung at the centre of the murder board. Alice Johnson had been a young, beautiful woman who, as far as they had been able to tell from the information they had gathered on her, had been very happily married with two small children. There was no evidence for any of the common reasons for murder. Her relationship with her husband seemed to be solid and she'd had a good job with no financial worries. She seemed to have been well liked at work, but there was no suggestion of anything beyond a working relationship, no hint of an affair or anything which would have led to her death. In fact, as far as Beckett and her team had been able to determine, Alice had never done anything wrong in her life worth recording.

The only sadness that they had managed to uncover in Alice's otherwise normal life had been her sister. Anna Dixon's DMV picture also hung on the whiteboard in front of Beckett and if it wasn't for the different ID details on the pictures there was no way she would have been able to tell the two sisters apart. Beckett had not met many identical twins in her life but each time she did it always surprised her just how identical twins could be. If it wasn't for the other pictures that she had seen of these two women together during the course of their investigation, she would have sworn before a judge that the pictures in front of her were of the same woman.

She would have been wrong of course. Beckett's eyes unfocused as her mind took her back two days, to their meeting with Anna Dixon. They had found out from Alice's distraught husband that Alice had a twin sister and that Anna had been diagnosed with terminal cancer 6 months ago. Anna only had a few weeks to live and so she and Castle had gone to the hospital where Anna was being treated, so that she could tell a dying woman that her twin sister was dead.

When they had been shown into Anna's room at the hospital it was immediately apparent that this woman was very ill, her frail body ravaged by the disease which was slowly eating her alive. Whilst Beckett could still see traces of her sister in Anna's features, the woman in front of her looked at least 20 years older than her twin had done. Her hair was gone and her face was sallow and waxy with cheekbones prominent beneath her paper-thin skin.

It had been a shock, seeing how different the twins had become as a result of Anna's illness. The poison which had been used to kill Alice had left her features essentially untouched and, used to death as she was, Beckett had been able to easily visualize how Alice would have looked before she had died. And even though she knew that just 6 months ago Anna would have looked exactly the same as her twin, it was hard to reconcile that mental image of Alice, a healthy 29 year old woman with everything to live for, with the frail, dying woman in front of her.

"She's dead isn't she," Anna had said before Beckett could introduce herself and Castle. "My sister is dead."

She had said it as a statement of fact, not as a question and she'd caught Beckett completely off-guard.

"How...?" was all Beckett had managed before the woman in front of her broke down in tears and all sorts of alarms started to go off. They'd been hustled out of the room pretty quickly at that point as nurses appeared to tend to the woman and the beeping machines which were keeping her alive.

They were eventually allowed back in half an hour later, after several admonishments from Anna's doctor to not stress his patient any further. He'd also insisted on being present before he would let her interview his patient again, to ensure she wouldn't upset her any further.

"I'm sorry for breaking down like that detective," Anna had said when Beckett and Castle sat themselves on either side of her. Her doctor had taken up station at the end of her bed, ostensibly looking at her chart. "I knew my sister was dead but to see the confirmation in your eyes...How, how did it happen?"

Beckett hated this part; there was never an easy way to tell someone that a loved one had been murdered, their life torn from their body before their rightful time.

"I'm sorry to tell you this Miss Dixon but it seems your sister was poisoned." A few words, no more. But Beckett had uttered variances on those words so many times, had been on the other side of them herself, and she knew just how devastating a few words could be. The words spoken to her and her dad had changed both of their lives, sending him in to 5 years of alcoholic hell and her on to a path which ultimately led to her being a cop, to being the one having to utter those few words to so many families, always wondering just how those lives will be altered by what had happened.

"Poisoned..." Anna whispered, a tear leaking down the side of her face. Anna's doctor stepped forward to check one of the machines attached to Anna and gave Beckett a warning look. She'd told him outside the room why she was there and what she had to tell Anna. He'd understood and agreed that Anna needed to know but had gone on and on about ensuring that she break the news gently, how Anna was very frail and her body could not stand to much emotional shock. It was clear signal that he would not allow them much more time with his patient.

"How did you know that Alice was dead Ms Dixon?" Beckett had asked. She'd known that Alice's husband had not spoken to her sister and whilst no murder in New York was ever a secret she'd been surprised that the news had reached Anna before they'd arrived.

"I felt her go," Anna said. "In here." Anna'd placed a thin looking arm with an IV drip attached across her chest, her fingers touching the place where her heart still beated despite the ravages of her illness.

"You...felt her die?" Beckett asked sceptically.

"Yes detective. My sister and I, we always knew what the other was thinking, how she was feeling," Anna said, somewhat wistfully. "If I stubbed a toe I knew Alice would ring me within a minute, asking what was wrong. I knew when Alice went into labour for the first time, even though I was in Atlanta and she was here in New York. We always knew...and then a few hours ago I felt something change, a feeling of absence, of loneliness which I had never felt before and I immediately knew that something was wrong. And as soon as you walked in it hit me, Alice was dead."

"The twin connection," Castle had breathed.

"The what?" Beckett'd said, looking across at her partner.

"The twin connection. You know, when twins are born there is a bond between them so deep that one knows what the other is feeling even if they are thousands of miles apart."

"Castle, that's ridiculous", she'd said without thought.

"No detective, it is very real." Anna had interrupted. "I don't blame you for your scepticism; you can't know what it is like to have a twin. But it is, it was, very real." Alice gave her a sad smile, another tear running down her cheek. "We always knew, always..."

Anna's voice had petered out then as she become lost in thought, presumably with memories of her sister. Beckett had been vaguely aware of the so called bond between twins but she gave it no more credence than any other form of mind reading or mysticism. Twins seeming to know what the other was thinking did not surprise her, two people brought up as closely as twins inevitably were would end up thinking the same way. And people wouldn't be people if they didn't read more in to the way in which twins seemed to know what the other was thinking than they did for ordinary siblings. As Castle would say, everyone loves a good story and a mystical bond between twins was a good story. But one twin knowing that the other was dead from across the city? No that she couldn't quite believe.

Beckett looked at the frail woman in front of her and all she could feel was sympathy for her. No one could look on someone as ill as Anna obviously was and feel anything but compassion for what she must be going through. It was hard to believe that this woman was capable of leaving her bed, let alone killing anyone, but Beckett's years of experience allowed her to imagine how hard it must be for Anna to have seen her healthy twin, walking around with her family. How much she must feel that it could have been her who was the healthy one. She could see how Anna might be driven into a desperate act by the unfairness of it all. It wasn't a good motive for murder, there never was a good motive, but Beckett had seen people killed for a lot less.

Looking at Anna Beckett wasn't sure what those thoughts said about her, that she was willing to believe that this dying woman could be so jealous of her twin sister's health that she would be driven to kill her. But Anna had openly admitted that she knew her sister was dead when by all rights she should have no way of knowing. Beckett closed her eyes briefly before forcing herself back into detective mode.

"Anna, can you think of any reason why someone would want to hurt your sister?"

"No detective, everyone loved Alice. She was perfect..." Anna trailed off again and her eyes started to drift close. Anna's doctor moved forward to examine his patient, gently checking her pulse and looking intently at one of the displays on the various machines in the room. After a moment or two he turned towards them.

"Detective, Mr Castle, I'm afraid that I'm going to have to ask you to leave now. Anna's condition means that she is in a lot of pain and as I'm sure you can see she does not have great reserves of energy. She needs to sleep, so that her body can deal with the shock of her sister's death."

Beckett took one look at Anna and briskly nodded. It was clear that they weren't going to get much more out of her today and if she was honest with herself she would be glad to be out of this room. She was used to being confronted with death on a daily basis but this was different. She suppressed a shudder as they left Anna to sleep.

Outside the room Beckett turned to Anna's doctor. "Doctor, is it possible that Anna could have left her room, gone to visit her sister?"

"Impossible," Anna's doctor had said without hesitation. "Anna's condition is such that any movement causes her extreme pain. She is on high doses of morphine and has not left that bed for several weeks. She would collapse and die if she tried. As it is, no matter what we do it is likely that it is only a matter of a few days, a week or two at most before her body finally just gives up. All we can try and do is to make her last few days as comfortable as possible."

Beckett's eyes refocused on the whiteboard in front of her. They had left at that point, but not before securing the reluctant permission of Anna's doctor for a second opinion on his patient's health. Whilst Beckett could easily believe every word he had said from what she herself had seen of Anna's condition, she would not be doing her job if she did not seek impartial advice. So when they'd gotten back to the precinct Beckett had filled out the forms requesting a medical opinion on Anna Dixon's condition. A copy of that form, along with the unsurprising confirmation that Anna Dixon had been medically unable to leave her hospital room for several weeks, now hung below Anna's picture.

And that was about as close as they had come to solving this case. Alice's husband had a water tight alibi and if she was any judge of character, and she knew that she was, he was not involved in her death. With no leads from her home, or from her work they were at a standstill. The sum total of what they knew was that the apartment Alice shared with her husband and two young boys had been trashed. There were several pictures of the place on the board in front of Beckett, showing the chaos caused by Alice's killer as they'd torn the apartment apart looking for something. All the evidence said that someone had been there, poisoned her and then trashed the place looking for something before escaping scot-free. But CSU had not found any prints that could not be accounted for and they had no idea if the killer had found what they'd been looking for; the husband hadn't been able to identify anything as missing.

In short, it was one big mystery with no clues and no leads. And tomorrow morning she'd have to go to Gates and recommend that the case be put on hold pending further evidence, effectively an admission that the killer had gotten away with it.

"Arrrgghhhh," she ground out quietly in frustration.

"Kate?" a voice asked softly.

Beckett jumped a foot in the air before whipping her head around. Castle was standing a few feet away from her, a laptop in his hands and a look of concern on his face.

"Castle," she grated at him in shock and anger. "Are you trying to give me a heart attack?"

"What, no...I..."

"What are you doing here Castle," Beckett demanded, hoping that her heartbeat would return from the stratosphere sometime soon. "I thought I told you to go home 2 hours ago!"

"You did, I did," Castle said defensively. "However," he continued, taking a step towards her. "I seem to remember that me going home was in exchange for you doing likewise...within half an hour as I recall?"

"Castle," Beckett said wearily, she knew that she'd promised him that she would go home but it wasn't as easy as that for her to walk away.

"I know, I know," he said soothingly, understanding thick in his voice as he took another step towards her so that he was now standing within arms' reach.

Beckett looked up at his eyes and she could see his concern for her radiating out of them and as always she did not know what to do with it. She could feel her own emotions boiling away, a turmoil that she could not understand or deal with. How or why he had this affect on her she had no idea. He drove her crazy and she kept pushing him away and yet he kept coming back and each time he came back she felt more alive than she had before. She couldn't deal with this right now, she wasn't able to process her own emotions let alone the promise she could see in his eyes.

"What do you want Castle?" She said brusquely, retreating from him to the relative safety of her desk.

Castle stood for a long moment looking at her and she wondered what he was going to say. A thousand emotions seemed to pass across his face before he finally sat down in his usual chair and turned to face her.

"I knew, just knew that you wouldn't let this case go so easily," Castle said, obviously choosing the safe path of 'back to business'. "So I went home, to get this." He indicated the laptop that he held in his hands.

"Your laptop?" Beckett asked, unsure what he was talking about.

"Yes, I had a story idea and I wanted to look at something before I told you about it."

"Couldn't it have waited until the morning Castle?" Beckett asked impatiently. The last thing she wanted to think about right now was some crack-brained idea he'd had for the next Nikki Heat book.

"Well my dear detective," Castle said grinning at her; he knew she hated him referring to her that way. "If you had gone home like you promised me you would then yes, it could have waited until tomorrow but as you're still here..."

"Castle," Beckett said threateningly. She didn't want him giving her any more grief over not going home as she'd promised. He was starting to make her feel a little guilty that she had lied to him and she didn't want him to know that.

"...so," he continued, blithely ignoring her warning tone. "I thought I would try my idea out and show it to you now."

"Castle, I really am not in the mood to hear about your latest plot to get Nikki and Rook into a situation where they end up having sex!" Beckett said, with more than a little touch of annoyance.

"Now why would you think I'd be writing about Nikki and Rook having sex detective?" Castle said, looking at her with false innocence plastered across his face.

Beckett stared back at his wide eyed gaze and knew that she was blushing slightly. Esposito and Ryan had been teasing her earlier in the day about one of the sex scenes in his last book and the more she threatened them the worse they had got. The scene was reminiscent of something that had actually happened between Castle and her, minus the sex of course, and the boys had just found out and were ragging her about it for all they were worth. Clearly they had gotten under her skin more than she had thought!

Castle coughed in to the now slightly awkward pause and continued without waiting for her to answer. "I think you might like this story but you must promise me before I show it to you that you won't get mad."

"I must promise you that I won't get mad _before _you'll show me? First of all that is not very promising to your claim that I will like it and secondly why should I care what you have written?"

"Ahh, well it's not the story itself which I think you might not like but what I propose to do with it. And I think you'll care because it is related to that," he said, indicating the murder board behind them.

"Our case?" Beckett said in surprise.

"Yeah. We've hit a complete dead end and even I, master of crazy theories as I am, am out of ideas. But I do have an idea about how we might be able to get some more leads but," he hesitated, "I'm...uh...not sure you'll approve so I thought I'd ask first."

Beckett blinked in surprise. Castle asking her before he did something foolish? That has got to be a first.

"Ok," she said cautiously, not sure where this was going but curious now.

"You've got to promise me you won't get mad first," Castle reminded her.

"Fine, 'I promise I won't get mad'," she said, holding her hand up in an almost scout like salute. "Now show me whatever damn stupid idea it is that you've been working on."

The mock seriousness in her voice made Castle smile and he opened his laptop and turned it towards her. Beckett looked at the screen curiously. She was surprised to see Castle's own website with a large picture of the author himself staring back at her, alongside the latest Nikki Heat cover art.

"Castle, if this is some kind of bad joke..." she began.

Castle looked over the screen. "Oops, sorry," he apologised and scrolled down a little. "This is not live yet," he said as he found what he was looking for and pushed the laptop in front of her again. "But I can make it live with a push of a button."

Beckett looked at the screen to a blog entry which he was indicating with one hand.

_'WHODUNNIT COMPETITION'_

_'As a treat for my many thousands of fans, waiting patiently for the next Nikki Heat book, I thought I would gift you all with a short story featuring your favourite detective and her faithful partner. But there is a twist, because all good stories must have a twist! The story is unfinished. 'Why is it unfinished?' I hear you ask, well not because I haven't finished it but because I want to challenge you, my fans, to a whodunnit competition! Yes that's right, I'm challenging you to solve a Nikki Heat mystery. _

_'What, I hear you ask, is the prize for this once in a lifetime opportunity? Well, for the person who gets closest to the right answer first prize will be a dinner with yours truly at the restaurant of your choice. Yes that's right, read the story below, guess who did it and submit your answers to win a dinner date with your favourite author. _

_Closing date is 24 hours from the posting of the story so get solving...'_

"Castle," Beckett asked looking at her partner who was grinning at her like a Cheshire cat. "What on earth has a competition to win a dinner with you got to do with our case and why should I care? Or be mad? Other than at you for wasting my time!"

"Ah but that's the brilliant thing. The story itself, when you read it, will sound a little familiar. I've changed certain things of course, to ensure that it works as a story and because, well, I've got to give it a little bit of flair otherwise my fans won't believe it is one of mine, but enough of it is there for us to get many hundreds of ideas..."

Beckett stared at her partner in confusion, what on earth was he talking about? Whodunnit stories, hundreds of ideas? Why would hundreds of ideas about one of his whodunnit stories interest her and what did that have to do with their case? Unless...no, he wouldn't have done that, he couldn't have done that. She looked at his grinning face, not even Castle would do that...would he?

"You didn't," she breathed. "Tell me you didn't write a whodunnit story based on our case?"

"Ok," He said, still grinning at her. "I will. But I'll be lying to you when I do."

"Castle, do you have any idea...you can't put people's lives out there like that, that's that's..." Beckett trailed off, unable to express just how wrong what he was suggesting was.

"Brilliant," Castle finished for her. He leaned forward, looking at her intently. "Trust me Beckett; I've changed enough to protect Alice and her family. No-one but you, I and her killer will understand the true meaning of the story but enough of the elements of what happened are there that any theories which my fans come up with could be valid.

"Yes, they will come up with a lot of nonsense as well and they'll be a lot of duplication but even if they come up with one idea that we haven't had, one thought which we've not considered it's got to be worth a shot. We both know that Gates is going to shut this case down tomorrow and once she does the chances of Alice's killer being caught drop to virtually zero. What have we got to lose, what has Alice got to lose?"

Beckett looked at her partner and with some disbelief she realised that she was actually considering his suggestion. He was right; they were smack out of ideas and in 12 hours this case would be closed and in all probability be lost to the 'unsolved' pile. That wasn't right and it wasn't fair but that's what was going to happen if they didn't do something.

"Castle," she said in a whisper, although there was no one around to hear them. "If the killer reads this..."

"What are the chances of that Kate? I know I'm popular but the chances of our killer being both a fan and looking at my blog in a 24 hour period are ridiculously small. However, lots of completely innocent mystery fans all around the world will read that story and some of them will even come up with good ideas, most of which we would already have had. But if they come up with just one good one that we haven't? That would be worth a meal and an evening of my time any day, even if it ultimately leads nowhere."

Beckett sat back, thinking hard. Could they do this? Could they get away with such an audacious plan? Only Castle could come up with something as mad as this, as out of the box and as outrageous as this. And that was it wasn't it, no-one would ever consider this; no-one would ever believe for one minute that they had turned to the legion of Castle's fans for ideas to solve a real life murder. It was mad, she was mad.

"The story must not identify or allow anyone to identify any of the people involved," Beckett said.

"It doesn't," Castle assured her, smiling brightly at her acceptance of his idea.

"You've written it already!" Beckett exclaimed in some surprise. Her mind had been so thrown by his idea that she'd only just cottoned on to the fact they were discussing his story as if it had already been written. But he'd only left the precinct a couple of hours ago, and he had to travel home and back here again in that time. He couldn't have written an entire short story in that time, could he?

"Hey," Castle said, looking a trifle hurt. "Professional writer, remember."

"But..."

"Look," Castle said with the boyish enthusiasm that often surrounded him when he discussed his art. "The hardest part of writing is the idea, the story. That already exists in this case. All I had to do was to change a few things around and bash out a thousand words or so. I can type fairly quickly when I set my mind to it. It won't be the best thing I've ever written and Gina will probably kill me for releasing it on my website but it will do the job."

Beckett was seriously impressed. She knew and loved Castle's books but she didn't really spend much time considering what it took for him to write them. Her penmanship was limited to filling in forms and providing factual, and somewhat dull, descriptions of crime scenes and the like. She knew that Castle was extremely good at what he did but she was much more used to being confronted with the end product of his work, not such a vivid and immediate demonstration of his talent.

"Show me," was all she said.

Castle leaned over and opened a document on his laptop before handing the computer back to her. Beckett took the laptop and was surprised to find that the feeling she normally had when reading one of Castle's books for the first time, a fluttering of anticipation in her stomach, was there in full force. Actually, this time it was worse than normal as she had never read one of Castle's books whilst the author himself sat a few feet away watching her. Turning away from him slightly so as to block his distractingly intense stare she concentrated on the story.

She read it from beginning to end twice. The first time through she'd become caught up in the tale and even though she knew it was based on fact the first thought she'd had when she reached the end was one of disappointment, not at the story itself but that it had finished without confirming the identity of the killer. Realising that she'd become lost in the story she'd scrolled back to the top and started again. It was amazing that he could take their case and in a few hundred words produce a simple tale that left her wanting for more, man this guy could write!

She paid much closer attention to what she was reading second time through, looking out for anything which would identify anyone or anything involved in the case. She should not have been surprised but he'd done a magnificent job of capturing the essence of the crime, the key points, whilst at the same time changing enough that only a few people would ever recognise that what he had written was based on fact. There was no doubt about it, she could've let him put this on his website and no-one would ever have suspected. It may even have generated the clue they needed to wrap this case up.

But that was no longer required because reading his story had already given her an idea, a thought which she wanted to explore with her partner there and then.

Beckett turned to look at Castle. He was staring at her with an expression on his face which took her a moment or two to identify. He was worried! Worried that she would not like what he had written. She couldn't stop the smile that spread across her face. She knew that she affected him; she saw it almost every day even if she didn't quite know exactly how to react to it. But sometimes it was easy to forget that for some reason, this wonderful man seemed to value her opinion above all others, with the possible exception of his daughter of course.

Beckett did something then that surprised even her. She leaned forward and kissed him on the forehead, a brief kiss, nothing more than a moment's touch of her lips to his head but it was something a good deal more intimate than such a simple thing had any right to be. As she leant back she couldn't help but notice the worried look which had been on Castle's face a moment before had now been replaced by one of shock, his mouth half open and his eyes on hers.

"Kate," he managed after a second or so.

"That," she said, a little breathlessly, "was a brilliant story. But we cannot release it to your website."

"What," Castle spluttered and Beckett laughed as he floundered, thrown completely by her kiss and then by her words.

She had him completely off balance and it was amazing just how much she loved seeing him thrown so completely into disarray. Beckett knew that she wasn't completely ready to give in to or accept her emotions as far as Castle was concerned but she knew there was something between them, something no mere words could ever define, even words as good as his. And besides, no woman alive could be completely blind the kind of affect she had on this man, not even one as emotionally messed up as she was.

"The only reason to put the story on you website was to get some new ideas, some clue to the case, yes?" Beckett asked, teasing him a little more.

"Y...Yes?" Castle managed, still several pages behind her.

"Well, that's no longer true so we don't need to publish your story. Which is a shame as your fans will be missing out on a treat."

Castle looked at her as though she had gone mad, probably not helped when she burst out laughing again at his bemused expression.

"I...I don't understand," he said.

"No? Well my dear writer, let me explain it to you," Beckett said, deliberately turning the phrase he liked to use to make her uncomfortable back at him.

* * *

It took a couple of days to put all the pieces together, it always did. This was the part of detective work that Castle hated but Beckett knew was essential. Building theories, working out possible plots and identifying suspects was all well and good but it was good solid, documented evidence that led to killers being arrested and jailed and that took time.

But eventually Beckett had all the information she needed, she knew what had happened to Alice and why she was dead. The knowledge brought her no joy but she was satisfied that she understood what had happened. After reviewing the case and her conclusions with Gates, securing agreement for her recommendation from her Captain, she found herself back at the hospital, back in the room with Anna and her ever present doctor.

"Detective," Anna said once she and Castle had sat down. "Have you found my sister's killer?"

It had only been a few days but Beckett could see that Anna's health had worsened since their last visit. Her voice was weak and her eyes lidded with what Beckett guessed was ever present pain, despite the amount of drugs being pumped into her body.

"We believe so," Beckett answered.

"Who?" Anna said, her eyes opening a little wider and seemingly a little more alert than a moment below.

"Alice," Beckett said, quietly but firmly enough to be heard by all in the room.

Anna hissed sharply at Beckett's words, her breath drawn in through her teeth and her eyes widening even more.

"Don't bring Alice, how dare you..."

A couple of alarms started to go off on the machines and Anna's doctor moved forward. "Out of the room detective."

"Not this time doctor," Beckett said firmly, her arms crossed.

The doctor gave her a brief, vexed look but quickly turned back to his patient and the warbling machines. It took a few minutes for the doctor and his nurses to bring Anna's condition back under control, throughout which Beckett and Castle stood quietly in one corner of the room. Eventually, once all the machines were quieted and Anna was stabilised Beckett and Castle moved back to her side. Her doctor stalked off to contact his boss, telling Beckett he was going to complain about her actions. Beckett let him go, uncaring. Nothing she would do here today would reflect badly on her, she knew that Gates had already spoken to the Hospital administration and that Anna's doctor would find Ryan and Esposito waiting with his boss.

"Anna, shall I finish the story now?" Beckett said when they were seated once more. "Actually 'story' is a very good word because it was one man's story that solved this case and ultimately led me here to you today." Beckett glanced over at Castle with those words and gave him a small smile. Castle smiled back to recognise her acknowledgement of his help in breaking this case.

"I'm in no position to stop you, am I" Anna said in a voice even weaker than when they had first entered.

"No, I guess not," Beckett agreed. "Well as I said, it was a good plan, one that almost had us fooled. We were only hours away from filing it as an unsolved case and unsolved cases rarely get dusted off and solved. In fact we were completely out of ideas, none of the information or evidence we had gathered made sense. Your sister was dead but we could find no reason why. Her place had been ransacked but there was no sign of forced entry and nothing appeared to be missing. There were no unexpected fingerprints or trace evidence that we could tie to her death and her husband had a solid alibi. In short, it looked like someone had been invited in to your sister's apartment, had slipped some poison in to her drink and after she had died, tore her place apart looking for something which they either did or did not find before departing, leaving no evidence that they had ever been there except for your sister's dead body. Are you with me so far?"

Anna said nothing, simply continued staring at her.

"So a perfect crime and we were this close," Beckett held up her thumb and forefinger about an inch apart, "to writing it off as an unsolvable. But then, I read a story, a story a lot like your sister's case but only a few would know that because the story had been altered enough to protect the identities of the individuals.

"But those alterations, brilliant as they were..." Beckett sighed inwardly as she caught Castle's grin out of the corner of her eye at those words. She would never hear the end of that statement, true though it had been. "...highlighted something to me which had been obvious from the start but which I had missed, hidden in plain sight as it was. Do you want to hear a part of that story?"

It was a rhetorical question as Beckett already had a printout of Castle's story in her hands, the relevant sentences highlighted so she could find them easily, although she thought that she knew this story so well by now that she might be able to quote it word for word from the top of her head.

'...when the police arrived they found Jane lying on her sofa, her face calm in death despite a slight pinkish hue to her skin. On the table in front of her were two half-empty glasses, filled with what looked like orange juice. Jane's apartment had been torn apart, books thrown carelessly across the floor along with the contents of several ransacked draws. The killer had obviously been desperate to find whatever it was that had made killing Jane worth the risk of discovery...'

Beckett finished reading from the page and looked up at the uncomprehending eyes of Anna. She was not surprised that the woman looked confused, on the surface there was nothing in Castle's words which would indicate that there was anything wrong, that the carefully crafted plan that her sister had put together had been exposed.

"That passage got me to thinking. If the killer had been so desperate to find whatever it was he was looking for how come the two glasses of orange juice were left untouched on the coffee table? Much like in this story, your sister's apartment had been ransacked, with books thrown to the floor and pictures torn from the walls. And yet despite the mess, which surrounded the table with two glasses on it completely, not one drop of liquid had been split...not one."

"But of course, that was impossible," Castle took up the story. "Or at least extremely unlikely. I mean, if I was tearing a place apart in a desperate hurry to find something before I'm discovered in the apartment of a woman I've just murdered I certainly wouldn't be too concerned about knocking over a glass or two. So that really only left one option, the place had to have been ransacked before your sister had been poisoned. It was the only logical explanation."

"And once we had concluded that," Beckett said, "it was only a small step to suppose that there was no second person in the room. That in fact your sister had torn the place apart herself, before taking the poison."

"But why?" Castle said, eagerly taking up the story again just as he had two nights ago when he and Beckett had thrashed this out for the first time, the words pouring out of them as they unconsciously took it in turns to tease out the next piece of the puzzle. "Why would your sister commit suicide and why would she try to disguise it as a murder? People have lots of reasons for committing suicide but from everything we had learned about Alice she certainly didn't seem to have any reason to kill herself. In fact, the only thing which seemed wrong in her life was that you were dying."

A tear had escaped Anna's eye during the last exchange but Beckett pressed on, wanting to complete the story as quickly as possible.

"The last time we were here you told us that there was a bond between you and your sister, that you felt everything that happened to her and visa versa. As you know I'm sceptical of that particular claim but it did make me think. You and Alice are identical twins, sharing essentially the same DNA and therefore presumably subject to the same genetic tendencies. And so what if Alice thought that she might have the same disease which was killing her sister? You two were close in the way only twins can be, mystical bond or not it must have been agony for Alice to see you decline from a healthy woman to your...uh...current state of health in only a few months."

More tears were leaking down Anna's face now and Beckett couldn't help but feel a little sorry for this woman. 6 months ago she had been a happy go lucky woman with most of her life ahead of her and a loving sister. Now she was alone in a frail shell of a body with a few pain filled days at best to live.

"And so," Castle said softly. "When Alice suspected that she was in the early stages of the same pancreatic cancer that was killing her sister she decided that she could not live through the pain that she could see you enduring, not without her sister to support her as she had done for you. Her husband could have no idea and who better to conduct the tests than her sister's doctor, who she knew so well and whom she could trust to keep her results away from her husband and children?"

"And so she came to you," Beckett said, "She knew that if she committed suicide then her insurance wouldn't pay up and so she couldn't leave her husband and her kids like that, but she also couldn't face going through the pain and agony she'd been forced to witness you endure."

"And between you, you hatched a plan," Castle said, understanding thick in his voice. "You couldn't leave this room and even if you could I don't think that you could actually have killed your sister. But you figured out between you that if Alice could fake her death, make it appear like she had been murdered then there could be a way out, a path that led to Alice escaping the same pain and agony you've had to endure but one which did not leave her family without financial support."

"She didn't want Jim and the boys to have to watch her suffer and waste away, as she'd been forced to watch me," Anna whispered. "She was so determined, so sure that an extra 6 months of life wasn't worth the pain and agony she would cause her family. So...so what happens now?" She asked.

Beckett looked across at Castle; they had talked that night until the boys had shown up at the precinct in the morning, debating what they should do if their theory was correct. Beckett was obliged to record everything they had learnt about Alice's death and they both knew that she would do what was right. She had told Castle once that life wasn't like one of his books and it was not up to her to decide what was right or wrong.

"Everything we have learnt has been added to your sister's file," Beckett said. "We can prove your sister had been diagnosed with early stage pancreatic cancer but we cannot prove that she took her own life. Only two people other than your sister knew of her condition. We've checked and are confident that your doctor had no reason or motive to kill Alice. We do know that he illegally submitted a test for her under your name, the test that confirmed your sister was suffering with the same cancer which is killing you, but that is not really my concern.

"I also suspect he turned a blind eye to what you were doing. He may or may not have known about it in advance but I think he probably worked it out quite quickly during or after our last visit. My detectives would have detained him by now and will be asking him all sorts of difficult questions, but I doubt we will find anything solid to hold him on. And that therefore leaves you.

"At this point it seems that we have a choice. We could consider Alice's death as suicide, as all evidence suggests she took her own life..."

Anna's eyes closed at Beckett's words, what little life left to her seemed to drain out of her face.

"...but," Becket continued, "I prefer to take the view that she was persuaded to kill herself. That although she died at her own hands her actions were the direct result of your brainwashing. Therefore, Anna Dixon, I am arresting you on suspicion of the second degree murder of your sister Alice Johnson. You do not have to say anything but anything you do say..."

Anna's eyes had sprang open as she'd listened to Beckett's final few words, the meaning of what she was saying energising her weak and frail body. A look of gratitude passed across her face and she smiled up at the detective as Beckett finished reading her her rights.

"Thank you," Anna said quietly, her closing her eyes once more.

There wasn't anything more to say. A uniform would be outside Anna's door but she could not be moved from this room. Gates had agreed that there was enough evidence to arrest Anna on suspicion of Alice's murder, although they had all known that there wasn't enough to convict her of the crime. It didn't matter, Anna would not live long enough for the case to go anywhere and once she died it would be impossible to prove whether Anna had brainwashed her sister into committing suicide or not. The file would simply be closed with Anna's charge of second degree murder on record. Beckett didn't know whether that would be enough for Alice to get her wish, to have found a way out which avoided a great deal of pain and agony for her and her family, but it was as much as she could do.

* * *

"That was horrible," Castle said a few minutes later as they drove away from the hospital and back towards the precinct. "In my time with you I've seen lots of horrible things but that must rank as one of the worst."

Beckett didn't answer but she had to agree. She could feel nothing but sympathy for the woman who they had left dying in that hospital or her twin who had taken her own life. Beckett had no idea what she would have done in Alice's shoes. Faced with a no-win scenario the twins had found a path which seemed to give Alice a way out, a way to avoid a great deal of hurt and pain to both herself and her family. Was it a good choice? That was a question Beckett didn't know the answer too, she just hoped that she would never, ever be put in to a position where she had to make a similar one.

Still, the case was over now and as with every case they had to move on. She glanced over at her partner, who was looking out the window and brooding. It was easy to forget that buried beneath his jovial playboy persona was one of the gentlest and most caring men she had ever met. Castle had had a very big heart and he had been badly affected by Alice and Anna's tragic story. Beckett's own heart reached out to him. Their relationship was complicated for sure but one thing was very clear to her right now, she couldn't stand to see him like this and she needed to cheer him up.

"So," Beckett said casually. "Where are you taking me for dinner then?"

"What?" Castle said, his head whipping round to hers, the brooding look on his face being replaced by one of puzzlement.

"Dinner? I seem to remember that you promised to take the winner of your Whodunnit competition out to dinner. I solved your whodunnit mystery Castle and I expect you to honour your promise."

Beckett watched the play of emotions across her partner's face as he worked out what she'd just said and what it meant. Ok, it wasn't a date as such, and there was no way she would ever let him refer to it as such; and she had kind of tricked him in to it - he had helped solve a lot of this mystery himself; and they'd been out to dinner together before; but there was no escaping the fact that this would be different. It would be a proper dinner in a proper restaurant, with just the two of them. Anything could happen...and even if nothing did, well it was worth it to see the smile that was slowly blossoming on Castle's face.


End file.
